Hemodynamic changes in growth retarded fetuses during maternal oxygen administration as predictors of fetal outcome.

The changes in fetal hemodynamics during maternal administration of 60% humidified oxygen were assessed by Doppler ultrasonography in 15 growth retarded fetuses characterized by abnormal blood flow velocity waveforms. During oxygen treatment, nine fetuses exhibited temporary hemodynamic modifications as expressed by a recovery toward the normal range of vascular impedance in the descending aorta and internal carotid artery, whereas no changes were found in the remaining six fetuses. In this latter group, a rapid deterioration of fetal condition occurred and all the fetuses were delivered by emergency cesarean section within 9 days from the Doppler examination. The absence of recovery of vascular resistance during acute maternal oxygen administration seems therefore to be a useful marker of imminent acute distress in fetuses with growth retardation secondary to chronic hypoxia.